Electric motor structure



y 15, 1952 G. H. KOCH 2350:5457;

ELECTRIC MOTOR STRUCTURE Filed Nov. 25, 1949 s Sheets-Sheet 1 FIGI.

INVENTOR Gustav H. Koch FlG.2.' m wy m ATTORNEY y 15, 1952 G. H. KOCH2,603,674

ELECTRIC MOTOR STRUCTURE Filed Nov. 25, 1949 a Sheets-Sheet 2 INVENTORWITNESSES:

Gustav H. Koch (51% I BY \lWMmk ATTORNEY July 15, 1952 G H. KOCHELECTRIC MOTOR STRUCTURE 3 Sheets-Sheet. 5

Filed NOV. 25, 1949 INVENTOR F l G 6 Gustav H Koch WITNESSES:

6. J4 \l. w. M i- 1k ATTORNEY stator.

Patented July 15, 1952 1mm PATENT OFF-ICE.

' Gustav H. Koch, Springfield, Massi, assignor to g WestinghouseElectric j Corporation, East Pittsburgh, Pa., a corporation ofPennsylvania Application- November 25, 19 50,"Serial'No, 197,527

fans. 1 a

My Patent No. 2,464,816 discloses an electric motor whichhas a casingdivided along an axial plane, the casing parts being provided withseats, the motor stator being placedin the seats of the lower casingpart and clamped therein by the pressure exerted by the upper casingpart which directly contacts the statorwhen the motor is assembled. Informing the-laminations for such a stator, it is important that thecircular hole for receiving the rotor be accurately located in relationto'the lands which seat against the seating portionsoi the casing; inorder to provide uniformity of the air gap between the rotor and the Inrelatively small motors, such as the two-pole motor illustrated in saidpatent, this accuracy can easily be obtained by forming the entirelamination in one punching operation.

In largenmotors, such as those having four poles, the lamination is solarge that thecircular hole for receiving the rotor and the seatinglands cannot readily be formed in one punchingoperation, that is, in onestation of the die, requiring that the rotor receiving hole be punchedin one station of the follow die and the stator seating lands be formedin another station of the die. This introduces the possibility ofimproper location of-the rotor receiving hole to the seating lands, withconsequent non-uniformity of the air gap.

- This invention provides an improved stator assembly for larger sizemotors, in which the stator is supported by pins the ends of which areseated in pin seats formed in the casing parts, and

which extend through small holes in the stator which can be punched inthe same operation or station of the die as the rotor receiving hole.

- An object of the invention is to provide an improved stator supportin'an electric motor.

A more particular object is to provide a stator support which accuratelylocates the rotor receiving hole of the stator.

The invention will now be described with reference to the drawings, ofwhich:

Fig. 1 is a side elevation of an electric fan having a motor embodyingthis invention;

Fig. 2 is a longitudinal, vertical section through the motor of Fig. 1;

v Fig. 3 is a sectional view along the line III--III of Fig.2; I

Fig. 4 is a perspective view of the motor stator and itssupporting pins;

Fig; 5 is a. plan view looking downwardly upon.

. 4- Glaims. (emu-252) 2 the lower part of the motor casing, with themotor and its components removed; and

Fig. 6 is a sectional view along the line VIVI of Fig. 2.

The fan illustrated by Fig. 1 comprises. an electric motor l0, fanblades ll attached to the motor shaft, and a fan guard 12 around theblades. The motor 10 is supported upon the base 13, and is adapted to beoscillated thereon by the conventional oscillating mechanism I4 and thecrank arm 15 attached thereto.

With reference to Figs. 2, 3 and 6, the casing of the motorof Fig. I isdivided generally in a plane extending parallel to the axis of' rotationof the fan motor, the plane of divisioninthe embodiment illustratedbeing spaced slightly above the axis, the casing thus being divided intoan upper casing part l6 and a lower casing part II. Each of these casingparts is of such construction as to permit the casting of all interiorsurfaces as described in detail in said patent.

The bearings l8 and 19 of the motor shaft 26 are seated in the bearingseats 2| and 22 formed in the lower casing part IT. The motor rotor 25is attached to the shaft 26 which is supported in the bearings 18 and [9which are held firmly in their seats by the spring members 233 and 29which extend over the bearings transversely of the motor. The springmembers 28 and 29 normally are flat but are bowed as illustrated by Fig.6 when the casing parts l6 and I! are bolted together. At theirintermediate portions, the spring members bear downwardly on thebearings. The downwardly facing shoulders 31 formed in the upper casingpart l6, bear downwardly upon the outer ends of the spring members. Therelative location of parts is such that the spring members aresubstantially deflected when the casing parts are bolted together Sothat the springs exert a substantial force pressing the bearings againsttheir seats. The upper and lower casing parts are bolted together by thebolts 32, two of which are disposed on opposite sides of each of thebearings l8 and I9 as illustrated by Fig. 6.

The lower casing part I! has the chamber 34 formed therein for thegearing of the oscillating mechanism, which includes a shaft 35extending downwardly through the bottom of the casing and having a crankportion 36 attached tothe connecting rod IS. The shaft 26 has a wormgear 31 formed on one end to drive the conventional gearing which, forsimplicity of illustration, is

not shown. The top of the chamber 34 is closed by the cover 38;whichiis. held in 'place by the transversely therethrough adjacent itsouter The openings 45 extend parallel to the edges. axis of rotation ofthe motor.

The openings 45 are relatively small so that,

Thus, the

openings 45 and the opening 4! are automatialignment, thereby dispensingwith the many rivets which ordinarily would beused to hold thelaminations inplace. The pins 38 also serve to support theastator inplace in the casing parts I8 and I! as will be described.

- The casing parts 6 and I! have formed therein the pin seats 50, two ofwhich are formed on each side of the rotational axis of the motor, thepin seats oneach side of the axis extending in alignment with axes whichextend parallel to the rotational axis.

The ends of the stator seating pins 48 are seated in the pin seats 50when the casing parts It and I! are bolted together, and support thestator tightly in place. In order to provide alignment of the shaft 25and the rotor 25 with the stator M, thepinseats 59 and the bearing seats2! and 22 in the lower casing part ii, are coined; that is, theyareformed in a coining press after the casting part I! is made. This,together with the fact thatthe openings in the stator for the pins 58and the opening 47 for the rotor are punched in one operation, providesaccurate alignment of the rotor centrally in the stator.

Due to the pin seats being located near the assembly bolts 32, lessassembly strain is placed on the casing parts, resulting in improvementin the permanence of alignment.

In assembling the motor, the shaft, the bear ings, the rotor and thestator with its assembled field windings, are placed in the lower casingpart I! with the bearingsfand the stator seating pins engaging theirrespective seats. The oscillating mechanism, including its gearing, isassembled, and the cover 38 is placed over the chamber 34. The springmembers 28 are positioned over the bearings I 8 and 19. The upper casingpart 16 is then positioned over the lower casing part with the shoulders3i resting upon the ends of the springs 28 and 29, and the spring 39resting upon the gear chamber cover 38. The bolts 32 are then insertedand tightened to pull the upper casing part 16 downwardly until the pins48 are seated in the pin seats 50 in'the casing part 56: As the 0ndlongitudinally extending upper casing part is drawn downwardly, theshoulders 3| bear downwardly on the ends of the springs 28 and 29 andcause them to bow as shown by Fig. 6, andto exert downward pressuresupon the bearings 18 and I 9, holding them firmly against their seats.

The casing parts l5 and I! are preferably formed so that when they aredrawn together by the bolts 32 to the positions shown by Figs. 2 and 3,there will be a slight clearance between same as indicated at 43. Thisinsures that, even with manufacturing tolerances or variations, it

will'always be possible to seat the upper pins 48 in their pin seats 50in the upper casing part.

The stator and the bearings are thus held in alignment by the engagementof the lower stator seating pins with their pin seats in the lowercasing part, and the engagement of the bearings with their seats in thelower casing part. The stator is held in position by the pin seats inthe upper casing part pressing against the upper stator seating pins andthus forcing the lower stator seating pins against their seats in thelower cas ing part. The bearings are also held in position by the uppercasing part by its pressure against the spring members 28 and 29 whichforce them against their seats.

It will thus be seen that I have provideda stator assembly in which theopening 4'! forreceiving the rotor is accuratelylocated to provideuniform air gap, because the stator is located by the openings 45whichare formedsimultaneously with the opening 4'! and, therefore, inaccurately spaced relation thereto. As will be noted from Fig. 3, theouter edges of the laminations are spaced from the inner surfaces of thecasing parts, so that such edges need not be accurately located.

While the invention has been illustrated in but one form, it will beobvious to those skilled in the art that it is not so limited, but issusceptible of various changes and modifications without departure fromthe spirit thereof.

What is claimed is:

1. A motor comprising a rotor having an axis extending longitudinally ofsaid motor, a stator core around said rotor, a casing divided into twolongitudinally extending parts, said stator core having a plurality ofspaced openings extending therethrough-parallel to said axis, aplurality of pin seats in each of said casing parts extending parallelto said aXis, and stator core seating pins extending through saidopenings into said seats.

2. A motor comprising a rotorhaving an axis extending longitudinally ofsaid motor, a stator core around said rotor, a casing divided into twolongitudinally extending parts, said stator core having two pairs ofoppositely disposed openings extending therethrough parallel to saidaxis, each of said casing parts having two pairs of pin seatsformedtherein, the seats of eachpair extending in alignment parallel tosaidaxis, and stator core seating pins extending through said openings.into said seats. a

3. A motor comprising a rotor having a rotary shaft extendinglongitudinally of said motor, bearings on said shaft, a'stator corearound said rotor, said stator core having two pairs of oppositelydisposed pins extending therefrom on both sides thereof, a casing aroundsaid stator core, said casing being dividedinto first and sec- H parts,the first of said parts having seats formed therein for'said bearingsand for the pins of one of saidpairs, and means for securing said casingparts together, the second of said parts having seats formed therein forthe pins of the other of said pairs.

4. A motor comprising a rotor having a, rotary shaft extendinglongitudinally of said motor, bearings on said shaft, a stator corearound said rotor, said stator core having two pairs of oppositelydisposed openings extending therethrough parallel to said shaft, twopairs of stator core seating pins extending through said openings, acasing around said stator, said casing being divided into first andsecond longitudinally extending parts, the first of said parts havingseats formed therein for said bearings and for the pins of one of saidpairs, means for securing said parts together, the second of said partshaving seats formed therein for the pins of the other, 15

of said pairs, and springs extending between said second casing part andsaid bearings for holding said bearings in said bearing seats.

GUSTAV H. KOCH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,120,427 Kronmiller June 14,1938 2,349,401 Beckwlth May 23, 1944 2,460,063 Cole Jan. 25, 19492,479,330 Fagley Aug. 16, 1949 FOREIGN PATENTS Number Country Date60,436 Netherlands Jan. 15, 1943

